CA2714067C - Sulfuration process of catalysts for hydrocarbon processing - Google Patents

Abstract

The object of this invention is a sulfuration process of a hydrocarbon treatment catalyst, including: - at least a first deposit step, at the surface of the catalyst, of one or several sulfuration auxiliaries of formula (I): (see formula (I) and at least a second step where the catalyst is put into contact with a sulfurated gaseous mixture containing hydrogen and a sulphur compound.

Description

Process for the sulphidation of treatment catalysts hydrocarbon The present invention relates to a process for the sulfurization of catalysts for the treatment of hydrocarbons in the field including petroleum refining and petrochemicals.
The present invention also relates to the use special sulphurization aids to improve performance of the gas phase sulphurization processes of catalysts for the treatment of hydrocarbons.
Hydrocarbon treatment processes carried out in refineries and / or petrochemical units include some number of treatments carried out possibly in the presence of hydrogen, which are intended to modify the structure of the molecules hydrocarbons and / or to remove hydrocarbon cuts from undesirable compounds such as in particular sulfur compounds, nitrogenous, aromatic, metallic. Can be cited as examples non-limiting, hydrocracking or hydroconversion processes, reforming, isomerization, alkylkation, hydrogenation, dehydrogenation and so-called hydrotreatment processes such as hydrodesulfurization, hydrodenitrogenation, hydrodearomatization, hydrodemetallation, hydrodeoxygenation.
These processes use specific catalysts, which comprise a porous support based on one or more oxides inorganic refractories, on which one or more catalytically active metals. These metals include the most often one or more metals of group VIII of the classification periodic element, and / or one or more Group VIB metals.
At the end of the manufacture of the catalyst, or at the end of its regeneration in the case of a catalyst already used, the metals are in the form of metal oxides which, as such, do not are not active.

2 To enable catalysts to be active in different hydrocarbon processing processes, it is necessary to proceed to a sulphidation of the catalyst, namely a treatment thereof at sulfur compounds, with the aim of converting oxides mixed sulphides, which constitute the active phase of the catalyst.
This sulphurization step is particularly important, since it conditions the activity of the catalyst in its use higher.
Many sulfurization processes have been described in the state of the technique.
In general, we distinguish the processes of liquid phase sulfurization, in which the catalyst is treated, in presence of hydrogen, by means of a liquid phase (usually a liquid hydrocarbon such as a gas oil) comprising compounds sulfurous; and gas phase sulfurization processes, in which the catalyst is treated with a gaseous mixture containing sulfur (typically in the form of hydrogen sulfide).
Thus, patent application EP 1 634 939 describes a method of sulphurisation carried out in the gaseous phase by means of a gas containing hydrogen sulphide (H2S) and hydrogen (H2), with a ratio of molar H2S / H2 greater than 4 and partial pressure of H2S at less than 1 kPa.
Many ways to improve performance processes for the sulphidation of catalysts have been described.
Thus, patent application EP 0 993 868, in the name of the Applicant describes a process for sulphurizing a catalyst hydroconversion of hydrocarbons, in the presence of hydrogen and less a sulfur compound. This process is characterized in that catalyst is also brought into contact with at least one compound hydrocarbon.
Patent Application EP 1 077 085, also in the name of the Applicant describes a sulphidation process which is characterized by that the catalyst is also precarboned so as to deposit in its pores a carbonaceous compound largely non leachable.

3 Furthermore, the patent application WO 01/76741 describes a process for sulphiding a catalyst containing at least one metal hydrogenating groups VI and / or VIII and an organic additive, in which the catalyst is, in a first step, brought into contact with a organic liquid, then, in a second step, put in contact with hydrogen and a gaseous compound containing sulfur, subject to less than 40% of the sulfur in the sulphurized catalyst has been brought by the organic liquid.
Continuing his research on sulphidation of hydrotreatment catalysts, the Applicant has now discovered that it was possible to improve sulfurization processes in the gaseous phase by depositing, prior to the sulphurization step proper, a particular sulfurization auxiliary on the surface of the catalyst. This discovery is the basis of the present invention.
Thus, the subject of the present invention is a method of sulfurization of a hydrocarbon treatment catalyst, comprising:
at least a first deposition step, on the surface of the catalyst, one or more sulfurization auxiliary (s) of formula (I):

O (I) in which R1 denotes a hydrogen atom or a group linear or branched, saturated or unsaturated hydrocarbon, comprising from 1 at 30 carbon atoms;
R2 denotes a linear divalent hydrocarbon group or branched, saturated or unsaturated, comprising from 1 to 30 carbon atoms, and may optionally contain one or more selected heteroatoms among the oxygen and nitrogen atoms;
R3 denotes a linear or branched hydrocarbon group, saturated or unsaturated, comprising from 1 to 30 carbon atoms; and

4 at least one second stage of bringing the catalyst into contact with a sulfur-containing gas mixture containing hydrogen and a sulfide compound different from the auxiliary of formula (I).
Unless expressly stated otherwise, the term "grouping" is hydrocarbon ", a group consisting solely of carbon and hydrogen.
Thus, according to the invention, the groups Ri (when of a hydrocarbon group) and R3 consist only of of carbon atoms and hydrogen and do not contain heteroatoms, while the R2 group may optionally contain also oxygen and / or nitrogen atoms.
Thus, according to the invention, the sulfurization auxiliary (s) of formula (I) comprise a single sulfur atom.
The sulfurization process according to the invention makes it possible to confer to the catalyst an excellent level of activity, superior to that found with certain methods of the prior art. In particular, Applicant has found that the presence of the sulfurization auxiliary of formula (I) on the surface of the sulfurized catalyst improved the activity catalyst.
In addition, the Claimant also found that the auxiliary sulfurization system of formula (I) facilitated the fixation of sulfur on the catalyst. In particular, the sulphidation step itself, by bringing the catalyst into contact with the sulfur-containing gas mixture, may be performed at a lower temperature than is generally practiced in the prior art.
The method according to the present invention comprises a first step in which one or more sulfurizing auxiliary (s) of formula (I) is (are) deposited on the surface of the catalyst.
Preferably, in the formula (I), R1 designates an atom hydrogen or a linear or branched hydrocarbon group, saturated or unsaturated, comprising 1 to 8 carbon atoms, and preferably 1 to 4 carbon atoms.
Also preferably, R2 denotes a grouping linear or branched divalent hydrocarbon, saturated or unsaturated, comprising 1 to 8 carbon atoms, preferably 1 to 6 atoms carbon, and may be substituted by one or more groups -OH, -OR, -NH2, -NHR, -NRR ', with R and R' designating alkyl groups having 1 to 4 carbon atoms and preferably 1 or 2 carbon atoms.
Also preferably, R3 denotes a grouping

Linear or branched hydrocarbon, saturated or unsaturated, comprising from 1 to 8 carbon atoms, and preferably 1 to 4 carbon atoms.
According to a preferred embodiment, in formula (1):
Ri represents a hydrogen atom or an alkyl group comprising 1 or 2 carbon atoms, and preferably R 1 denotes a hydrogen atom;
R2 denotes an alkyl group comprising from 1 to 5 atoms of carbon which may be substituted by one or more groups -OH;
- R3 denotes an alkyl group comprising 1 or 2 atoms carbon, and preferably R 1 denotes a methyl group.
According to a particularly preferred embodiment of the invention, the sulfurization auxiliary of formula (I) is 2-4-methylthiobutanoic hydroxy, that is to say that in formula (I):
Ri denotes a hydrogen atom, R2 denotes a group -CHOH-CH 2 -CH 2 -, and R 3 denotes a methyl group.
This embodiment is particularly advantageous in the extent that the sulphurization aid is easy to prepare and little expensive, since it is a compound close to the amino acid methionine, which can be synthesized by analogous pathways.
In addition, this sulfurization auxiliary has the advantage to be perfectly soluble in water, which allows its use as an aqueous solution.
The sulfurization auxiliary of formula (I) is deposited at catalyst surface by contacting the catalyst with this auxiliary. There are several ways to proceed, for example in bringing the catalyst into contact with the pure sulphurization aid (especially in liquid or gaseous form), or with a composition containing the sulfurization auxiliary within a carrier fluid which can be liquid, gaseous or supercritical. Preferably, the auxiliary sulfurization of formula (I) is deposited by placing the catalyst in

6 contact of a solution or suspension of said auxiliary in a carrier liquid.
Thus, particularly preferably, one proceeds by impregnation of the catalyst with a solution or a dispersion of the sulfurization auxiliary in an aqueous liquid and / or appropriate organic.
According to a particularly advantageous embodiment of the invention, the sulfurization auxiliary (s) of formula (I) is (are) deposited on the catalyst by impregnation with one or several aqueous solution (s) of the auxiliary (s).
Preferably, the aqueous solution (s) used comprises (include) no organic co-solvent.
It is possible to proceed by dry impregnation of the catalyst (that is, to say by means of a solution whose volume is less than or equal to porous volume of the catalyst), by impregnating the catalyst with presence of excess solution, or by soaking the catalyst in an excess of solution.
This contacting of the catalyst with the auxiliary of Sulfurization can be instantaneous or last up to 20 hours. Of preferably, this placing in contact lasts approximately 2 hours, preferably about 1 hour. It can be performed at a pressure ranging from atmospheric pressure at 5 bar, preferably at pressure atmospheric, and be carried out at a preferred temperature from room temperature to 100 C.
If any solvent remains, it is then removed for example by heating so as to evaporate, or by suction, or by drying by means of a gas stream, possibly in the presence of heater. In any case, the removal of the residual solvent where appropriate must be carried out in such a way as to preserve the completeness, or at least a substantial part of the deposited sulphurization aid on the surface of the catalyst, and prevent it from decomposing.
In general, the first step must be carried out under conditions allowing the deposition on the surface of the catalyst a sufficient amount of sulfurization auxiliary of formula (I), in order to obtain the desired activity gain.

7 Preferably, at the end of the first step, the total quantity of sulfurization auxiliary (s) of formula (I) deposited on the surface of the catalyst, expressed as the ratio of the molar amount of compound (s) of formula (1) on the total molar amount of metals catalytically active agent is at least 0.01 moles of compound (s) formula (I) per mole of catalytically active metals. Preferably, this amount is between 0.01 and 10 moles of compound (s) of formula (I) per mole of catalytically active metals, plus preferably between 0.05 and 5 moles and even more preferred between 0.1 and 1.5 moles.
For example, when the catalyst includes, as metals catalytically active group VIII and VIB metals, the total amount of sulfurization auxiliary (s) of formula (I) deposited at the catalyst surface at the end of the first stage is preferably at least 0.01 moles of compound (s) of formula (I) moles of Group VIII and VIB metals. Preferably, this quantity is between 0.01 and 10 moles of compound (s) of formula (I) moles of groups VIII and VIB, more preferably between 0.05 and 5 moles and even more preferably between 0.1 and 1.5 mol.
The method according to the present invention also comprises less a second step, during which the catalyst is put into contact with a gas mixture containing sulfur, containing hydrogen and a sulfur compound different from the sulfurization auxiliary of formula Mr.
Advantageously, the sulfur compound is sulphide of hydrogen (H2S), or a compound capable of releasing sulphide of hydrogen by hydrogenolysis under the operating conditions of the second step. Among the compounds that can be used for this purpose, example elemental sulfur, CS2, organic compounds sulfur compounds different from the sulfurization auxiliary of formula (I), such as mercaptans, sulphides, disulfides, polysulfides, thiols, thiophenes, sulfoxides.
This sulfur compound can be introduced together with hydrogen, or previously deposited on the catalyst.

8 Thus, according to a first embodiment, the catalyst is contacted simultaneously with the hydrogen and the sulfur compound, by contacting the catalyst with a gaseous mixture preconstituted, containing hydrogen and the sulfur compound.
Preferably, this gaseous mixture contains hydrogen and hydrogen sulphide. For example, one can proceed from as described in patent application EP 1 634 939.
According to a second embodiment, the catalyst is, in a first time, brought into contact with the sulfur compound, for example by depositing it on the surface of the catalyst, then, in a second, the catalyst is brought into contact with a gas containing hydrogen, under conditions such that the compound sulphide decomposes and gives rise to hydrogen sulphide.
This gives the gas mixture sulfur.
In this embodiment, the sulfur compound is preferably selected from elemental sulfur and the compounds sulphides, in particular mercaptans, sulphides, disulfides, polysulfides, sulfoxides.
The sulfurized compound can be deposited on the catalyst as it is, in liquid or gaseous form. It can also be filed in solution or in suspension within a gaseous vector fluid or liquid. It is thus possible to proceed by impregnating the catalyst with means of a solvent containing said sulfurized compound, followed by possible drying to evaporate the solvent. We can proceed, for example, as described in the EP patent application 0 707 890.
The preferred embodiment of the second step is the one wherein the catalyst is contacted with a gaseous mixture sulfur, preconstituted, containing hydrogen and sulphide hydrogen.
Whatever the particular embodiment of the second step, the amount of sulfur compound used is such that the sulphide of hydrogen represents from 5 to 70% by volume of the sulfide mixture hydrogen + hydrogen, preferably 10 to 60% by volume.
The sulfur-containing gas mixture may, in addition to hydrogen and sulfur compound, also include one or more other gases,

9 such as, in particular, inert dilution gases, for example nitrogen. Such additional gases may for example represent 5 at 80% by volume of said gaseous mixture.
That the sulfur compound be introduced directly with hydrogen, or generated from a previously deposited compound on the catalyst, the actual contacting of the catalyst with the gaseous sulfur mixture is carried out at a temperature ranging from 150 to 500 ° C, preferably from 200 to 350 ° C.
Preferably, the temperature varies over time. So, one can proceed in at least two stages, a first stage of progressive rise in temperature, followed by a second step of bearing at a temperature ranging from 200 to 350 C.
According to a particularly preferred embodiment and advantage of the invention, the actual contacting of the catalyst with the sulfur gas mixture is carried out at a temperature below 300 C, and more preferably below 275 C.
Indeed, thanks to the presence of the sulfurization auxiliary of formula (I) at the catalyst surface, the treatment of the catalyst with the gaseous sulfur mixture is more efficient, and can be carried out at a lower temperature than that usually practiced in art which is usually at least 300 C.
The pressure is usually between the pressure atmospheric and 100 bars. Preferably, the contacting of the catalyst with the sulfur gas mixture is carried out at pressure atmospheric.
Said second step can be carried out in a fixed bed or in a bed mobile, for example in fluidized bed or bubbling, or in an oven rotary. In the case of a moving bed, the sulfur-containing gas mixture can circulate in co-current or against the current of the catalyst bed, preferably against the current.
The amount of sulfur incorporated in the catalyst during said second step depends on the amount of active metals present in the surface of the latter. Preferably, the amount of sulfur incorporated represents from 50 to 200%, preferably 80 to 120%, more preferred from 90 to 110% of the stoichiometric amount of sulfur necessary for the active metals to be fully form of metal sulphides.
For example, in the case of a catalyst with active metals are cobalt and molybdenum, the sulphide forms corresponding to a 5 stoichiometry of 100% can be likened to respectively CoS
and MoS2.
In addition, the process according to the invention is preferably carried out under conditions such that the sulfurized catalyst obtained by means of of said process contains at least 1% by weight of carbon from

The sulfurization auxiliary of formula (I), with respect to the total weight of the catalyst in oxide form. Preferably, this content is from minus 1.5% by weight.
The measurement of the carbon content from the auxiliary formula (I) can be performed by measuring the carbon content of the sulphurized catalyst, correcting the loss on ignition at 500 C ( detailed below) to express it in relation to the weight of the catalyst oxide, and subtracting from this content the possible carbon content of the initial catalyst before treatment using the method according to the invention.
In the method according to the present invention, said second step is performed after the first step. It can be performed directly after the first step, or separated by one or several intermediate step (s).
The sulfurization process according to the invention can thus, in addition to two steps described above, optionally include one or more additional steps, which can be done before and / or after said first and second steps, or alternatively be interposed between these two steps.
Thus, the method according to the invention may also comprise after said first step, a step of drying the catalyst, which can be carried out at a temperature ranging from 80 C to 350 C, preferably 100 C to 200 C, in the open air or in the presence of a flow gaseous air, inert gas such as nitrogen, or any other gas appropriate.
In addition, said second step is generally followed by a step cooling, during which the catalyst is reduced to

11 ambient temperature, or at a temperature close to the temperature room. This cooling, usually done gradually, can be carried out in the presence of the gas mixture sulfur, or any other suitable gas, for example hydrogen, an inert gas such as nitrogen, oxygen, or a mixture of such gases, or different gaseous mixtures used successively.
Thus, we can proceed to a first phase of cooling gas mixture sulfur, followed by a second cooling phase under inert gas, for example nitrogen.
According to a preferred embodiment of the invention, the method further comprises, after said second step, a step of catalyst passivation, which is preferably a passivation oxidizing.
This oxidative passivation consists in bringing into contact the catalyst with oxygen or a gaseous mixture containing oxygen. A gaseous mixture containing less than 30% oxygen. This gaseous mixture may especially be the air. The contact of the catalyst with the oxygen-containing gas can to be done in several stages, with gradual increase of oxygen content over time.
The passivation step is preferably carried out at a temperature below or equal to 150 C, for a period generally less than 24 hours. It can in particular be carried out simultaneously with the catalyst cooling step carried out at the outcome of the second step.
In the case of an ex situ sulphurisation process, the passivation has the advantage of reducing the trend pyrophoric phase sulfides present on the surface of the catalyst, and thus allow easy transfer or storage thereof, by example in metal drums or other types of containers.
The sulfurization process according to the invention can also understand a precarbonation stage, during which is deposited in the pores of the catalyst a major carbon compound non-leachable part, as described in the patent application EP 1 077 085, or one or more hydrocarbon compounds, different

12 of the sulfurization auxiliary of formula (I), as described in the patent application EP 0 993 868.
Such a step can then be performed before said first step, simultaneously with said first step, between the first and the second step, or simultaneously with said second step.
However, according to a preferred embodiment of the invention, the sulphidation process does not include any deposit on the surface of the catalyst, carbon sources other than the sulfurization auxiliary of formula (I). In particular, the process according to the invention preferably includes no deposits of hydrocarbons other than the sulfurization auxiliary of formula (I).
The process according to the present invention makes it possible to sulphurize catalyst for the treatment of hydrocarbons, in the fields refining and petrochemicals.
These catalysts comprise at least one active metal such as in particular a hydrogenating metal, deposited on a support based on a or several refractory mineral oxides.
By hydrogenating metal is meant a metal of groups VIII and VIB of the periodic table of elements.
Preferably, the catalysts treated by the process according to the invention are catalysts containing at least one metal of the Group VIII of the Periodic Table of Elements, as cobalt, nickel, iron, platinum, palladium, associated with at least one Group VIB metal such as, for example, molybdenum, tungsten, chromium. The metal or metal content of group VIII
is generally between 0.1 and 10% by weight relative to total catalyst weight, and the metal or metal content of the group VIB is generally between 1 and 20% by weight with respect to total weight of the catalyst.
The hydrogenating metal (s) is (are) deposited on a support based on one or more refractory mineral oxides such as in particular aluminas, silicas, silica-aluminas, zeolites, zirconia, titanium and boron oxides, and mixtures of such oxides.
The process according to the invention is particularly suitable for sulphidation of catalysts containing metal associations

13 CoMo, NiMo, NiW, NiCoMo, deposited on supports based alumina.
The catalysts treated by means of the process according to the invention may, in addition to the hydrogenating metal or metals, contain all the ingredients additional information. They can thus contain for example, and without limitation, one or more halogenated, borated compounds, phosphorus, one or more elements selected from those IIIB, IVB, VB of the Periodic Table of Elements, The process according to the present invention is suitable particularly with the sulphidation of catalysts containing no organic additive. Thus, it is particularly suitable for sulphurization of catalysts for which the difference between the loss at fire at 500 C and the loss on ignition at 150 C is less than or equal to 2%
weight, based on the weight of the initial catalyst.
In a manner well known to those skilled in the art, the expression loss on ignition (or LOI) means the loss of mass resulting from the heating of a material, due to departure of volatile matter.
A catalyst containing organic materials such as organic additive has a significant loss on ignition at 500 C, resulting from the decomposition of these organic materials. In addition, made of their large specific surface and their character hygroscopic, catalysts can absorb a quantity negligible amount of water from, inter alia, the humidity of the air, which is characterized by a loss on ignition at 150 C which can range from 5 to 10%
in weight. Thus, to determine whether or not a catalyst contains a organic additive, it is appropriate to consider the difference between the at 500 C and loss on ignition at 150 C.
Hydrocarbon catalysts are available usually in the form of small solid particles such that balls, more or less cylindrical particles, extruded.
They have a specific surface, measured by the BET method, generally between 100 and 300 m 2 / g, a pore volume, determined by nitrogen adsorption, ranging from 0.25 to 1 ml / g, and a average pore diameter, determined by nitrogen adsorption, ranging from 7 to 20 nm.

14 The process according to the invention is suitable for the sulfurization both new catalysts, only spent catalysts that have been previously regenerated.
Once treated using the process according to this invention, the catalyst is ready for use, and can be advantageously used directly in the treatment process of hydrocarbons for which it is intended.
It is also possible to carry out a second treatment of sulphidation of the catalyst, carried out especially in situ, immediately before using the catalyst. It may be in particular a sulfurization treatment carried out in the presence of hydrogen by passage through the catalyst of a liquid phase containing sulfur, typically a cut of sulfur and / or enriched hydrocarbons in sulfur-containing hydrocarbons, such as, for example, a distillate optionally additive in dimethyl disulphide.
Thus, the method according to the invention can be used as pre-sulphidation process, in order to precondition the catalyst, to decrease the intensity and duration of the final sulphurisation treatment performed in situ, thus saving time, and increasing efficiency of the hydrocarbon treatment process.
The catalysts obtained by means of the process according to the invention can be used in any industrial process involving a sulfur catalyst. They are specifically intended for hydrocarbon processing processes such as slices hydrocarbons produced from natural gas, coal, and hydrocarbons of vegetable origin.
As non-limiting examples, the processes hydrocracking or hydroconversion, reforming, isomerization alkylation, hydrogenation, dehydrogenation and so-called hydrotreatment processes such as hydrodesulfurization processes, hydrodenitrogenation, hydrodearomatization, hydrodemetallation, hydrodeoxygenation.
The process according to the present invention is suitable particularly in the sulphidation of catalysts for processes of hydrotreating of petroleum fractions, and in particular to the process hydrodesulfurization.

The present invention also relates to the use of the sulfurization auxiliaries of formula (I) as described above, in order to to improve the performance of sulfurization processes catalysts for the treatment of hydrocarbons. In particular, thanks 5 to the use of this particular aid during the process of sulphurization, a catalyst is obtained whose activity is improved.
Another subject of the present invention is the use of a sulfurization auxiliary of formula (I) as described above in the processes for the sulphidation of catalysts comprising one or more 10 metal oxides, in order to improve the stoichiometry of the sulphidation of the metal oxide (s).
It should be noted that the sulfurization auxiliary of formula (I) can be used in any sulfurization process, for example in liquid phase or gas phase. This use is

Particularly beneficial in the case of sulfurization processes in gas phase.
The following examples are given purely illustrative of the present invention.

EXAMPLES
Comparative Example 1 This example was made from a catalyst conventional hydrotreater CI, containing 23.1% by weight of M003 and 4.2% by weight of CoO supported on gamma alumina. he contains less than 0.1% by weight of carbon.
This catalyst has a difference between the loss on ignition measured at 500 ° C. and the loss on ignition measured at 150 ° C. of 1.5% by weight.
The loss on ignition was evaluated as follows: an initial mass known catalyst (m,) is introduced into a furnace at a temperature T given for 2h. The catalyst is then removed from the oven, placed in a desiccator to cool it without resuming of moisture, then weighed. The final mass mf is then obtained. The loss fire is then calculated as follows:

16 Loss on fire (TC) = mi -M ~ * 100 m, Table 1 below summarizes the characteristics of the starting catalyst Cl.
Table 1 MoO3 content (% by weight) 23.1 CoO content (% by weight) 4,2 Carbon content (% by weight) <0,1 Loss on ignition at 500 C (% weight) 3,5 Loss on ignition at 1 50 C (% weight) 2 Loss on fire at 500 C- Loss on fire at 150 C 1.5 This catalyst C1 was sulphurized at atmospheric pressure by a gas mixture H2S / H2, with a partial pressure of H2S of 0.4 and a gas hourly volume velocity (VVH) of 300 h -1. The ramp temperature is 5 C / min up to 320 C, with a plateau of 2 hours at this temperature. The sulfurized sample S 1 was thus obtained. Analyses performed on the sulphurized catalyst Si have made it possible to obtain following results Table 2 Loss on ignition at 500 C (% by weight) 4.8 Carbon content relative to the weight of <0,1 oxide catalyst (% by weight) Sulfur content relative to the weight of 10.4 oxide catalyst (% by weight) Stoichiometry S (%) 86 Stoichiometry is the ratio of the measured sulfur content (relative to the weight of oxide catalyst) on the sulfur content calculated, corresponding to a complete sulphidation of the oxides (assuming the formation of the sulphide forms CoS
and MoS2).

17 Comparative Example 2:

This example was made from the same catalyst conventional hydrotreating Cl, described in Example 1.
This catalyst Cl was sulphurized at atmospheric pressure by a gas mixture H2S / H2, with a partial pressure of H2S of 0.4 and a 300 hr VVHbaZ. The temperature ramp is 5 C / min up to 225 C, with a plateau of 2 hours at this temperature. The sample sulfide S2 was thus obtained.
The analyzes carried out on this sulphurized catalyst S2 allowed to obtain the following results Table 3 Loss on ignition at 500 C (% weight) 3.1 Carbon content relative to the weight of <0,1 oxide catalyst (% by weight) Sulfur content based on the weight of 8.2 oxide catalyst (% by weight) Stoichiometry S (%) 68 Comparative Example 3 This example was made from the same catalyst conventional hydrotreating Cl, described in Example 1.
100 g of catalyst C1 were impregnated with 10 g of a hydrocarbon (150 Neutral base type mineral oil, mass volume 0.87 g / cm 3 and viscosity 121 mm 2 / s) to provide the Al catalyst.
This catalyst Al was sulphurized at atmospheric pressure by a gas mixture H2S / H2, with a partial pressure of H2S of 0.4 and a 300 hr VVH52Z The temperature ramp is 5 C / min up to 225 C, with a plateau of 2 hours at this temperature.
The S3 sulfur sample is thus obtained. Analyses carried out on the sulfurized catalyst S3 made it possible to obtain the following results:

18 Table 4 Loss on ignition at 500 C (% weight) 12.8 Carbon content based on the weight of 8.3 oxide catalyst (% by weight) Sulfur content based on the weight of 8.0 oxide catalyst (% by weight) Stoichiometry S (%) 66

19 Example 4 according to the invention This example was made from the same catalyst conventional hydrotreating Cl, described in Example 1.
100 g of the catalyst C1 were impregnated with saturation of porous volume at room temperature by a solution obtained by mixture of 14.2 g of a commercial solution containing 88% by weight of acid 2-hydroxy-4-methylthiobutanoic acid (ie 12.5 g of 2-hydroxy-4-methylthiobutanoic) and 36 g of demineralised water. After impregnation, the sample was dried under nitrogen in an oven at 140 C, to obtain the catalyst A2.
This catalyst A2 was sulphurized at atmospheric pressure by a gas mixture H2S / H2, with a partial pressure of H2S of 0.4 and a VVHgaz of 300 h-1. The temperature ramp is 5 C / min up to 320 C, with a plateau of 2 hours at this temperature. The sample S4 sulfur was thus obtained. The analyzes carried out on this catalyst S4 sulphide produced the following results Table 5 Loss on ignition at 500 C (% weight) 8.3 Carbon content based on 2.7 weight oxide catalyst (% by weight) Sulfur content relative to the weight of 12.8 oxide catalyst (% by weight) Stoichiometry S (%) 106 Example 5 according to the invention The catalyst A2 described in Example 4 was sulfurized to atmospheric pressure by a gas mixture H2S / H2, with a partial pressure of H2S of 0.4 and a VVHgaz of 300 h-1. The ramp temperature is 5 C / min up to 225 C, with a plateau of 2 hours at this temperature.

The S5 sulfur sample was thus obtained. Analyses performed on this S5 catalyst resulted in the results following:

5 Table 6 Loss on ignition at 500 C (wt.%) 15.9 Carbon content based on the weight of 4.9 oxide catalyst (% by weight) Sulfur content relative to the weight of 12.6 oxide catalyst (% by weight) Stoichiometry S (%) 104 Example 6 Performance in Hydrodesulfurization of the Catalysts of the 10 examples 1 to 5:

The hydrodesulphurisation activity of hydrocarbons of each sulphurized catalyst SI, S2, S3, S4 and S5 was then evaluated, by means of a pilot test.
The load used is a straight run diesel, which presents the following characteristics:

Sulfur content (ppm by weight) 12200 Nitrogen content (ppm by weight) 94 Density (g / mL) 0.837 The volume of catalyst used for the test was 10 mL.

After a wetting period of 3 hours at room temperature by the diesel fuel, the temperature rise is carried out with a ramp of 40 C / h up to the test temperature, with diesel fuel at a hourly volume velocity of 2h-1, with an H2 / gas oil ratio of 300 (NL / h) / (L / h) and a total pressure of 3 MPa.
The test conditions are then the following: pressure of 3 MPa, H2 / gas oil ratio of 300, VVH = 2h-1; the test was done,

21 for each sample, at a unit temperature of 340, 345 and 350 C.
The sulfur content of the charge is measured at the unit outlet using a UV fluorescence analyzer. The obtained results are shown in Table 7 below.

Table 7 Auxiliary Temperature Catalyst Output S Content sulphurization sulfurization unit (in ppm) (C) at 340 '> C at 3450C to 3500C
S1 no 320 154 78 38 S2 no 225 265 151 70 S3 oil 150N 225 238 133 62 S4 2-hydroxy acid 4- 320 82 41 19 meth lthiobutanoï ue S5 2-hydroxy acid 4- 225 90 45 22 methylthiobutano'i ue The results above demonstrate that catalysts S4 and S5, sulfurized by means of the process according to the invention, exhibit a activity in hydrodesulfurization very significantly improved compared to sulphidized catalysts Si, S2 and S3 by means of processes according to the art prior. This increase in activity is observed even when the temperature of the sulphurisation itself (treatment with gas mixture) is lowered substantially from 320 C to 225 C.
In addition, the analyzes carried out on the samples of catalysts demonstrate that the use of the sulfurization auxiliary according to the invention makes it possible to substantially improve the sulphidation stoichiometry of the metal oxides present in the catalyst surface.

Claims (17)

22 1. Process for the sulphidation of a catalyst treatment hydrocarbon composition, comprising:
at least a first deposit step, on the surface of the catalyst, one or more auxiliary sulphurization of the ormule (I):
in which :
denotes a hydrogen atom or a hydrocarbon group linear or branched, saturated or unsaturated. comprising from 1 to 30 alomes of carbon;
R2 denotes a linear divalent hydrocarbon group or branched, saturated or unsaturated, comprising from 1 to 8 carbon atoms.
substituted with one or more -OH, -OR, NH2, -NHR, -NRR 'groups, with R and R 'denoting alkyl groups comprising from 1 to 4 carbon atoms;
R3 denotes a linear or branched hydrocarbon group, saturated or unsaturated, comprising from 1 to 30 carbon atoms; and at least one second stage of bringing the catalyst into contact with a sulfur-containing gas mixture containing hydrogen and a compound sulfide different from the sulfurization auxiliary of formula (I). 2. Method according to claim 1, characterized in that in the formula (I), R1 denotes a hydrogen atom or a group linear or branched hydrocarbon, saturated or unsaturated, comprising carbon atoms. 3. Process according to any one of claims 1 and 2, characterized in that in formula (I), R2 denotes a group linear or branched divalent hydrocarbon, saturated or unsaturated, from 1 to 6 carbon atoms, substituted by one or more -OH groups, -OR.
-NH2, -NRR ', with R
and R 'denoting alkyl groups comprising 1 to 4 carbon atoms. 4. Method according to any one of claims 1 to 3, characterized in that in formula (I), R3 denotes a grouping linear or branched hydrocarbon, saturated or unsaturated, comprising from 1 to 8 carbon atoms. 5. Method according to any one of claims 1 to 4.
characterized in that the sulfurizing auxiliary of formula (I) is the acid 2-hydroxy-4-methylthiobutandic acid 6. Process according to any one of claims 1 to 5, characterized in that the sulfurization auxiliary (s) of formula (I) is (are) deposited on the catalyst by impregnation with one or several aqueous solution (s) of (these) auxiliary (s). 7. Method according to any one of claims 1 to 6, characterized in that the sulfur compound employed during the second stage is hydrogen sulphide (H2S), or a compound capable of release hydrogen sulfide by hydrogenolysis. 8. Process according to claim 7, characterized in that the catalyst is, in a first step, brought into contact with the compound sulfide, by depositing it on the surface of the catalyst, and then, in a second time, the catalyst is brought into contact with a gas containing hydrogen, under conditions such that the sulfur compound is decomposes and gives rise to hydrogen sulphide. 9. Process according to claim 7, characterized in that the second step is performed by contacting the catalyst with a pre-constituted sulfur gas mixture containing hydrogen and Hydrogen sulfide. 10. Process according to any one of claims 1 to 9, characterized in that the contacting of the catalyst with the mixture sulfur gas is carried out at a temperature below 300 ° C. 11. Method according to any one of claims 1 to 10.
characterized in that it is carried out under conditions such that the The sulfurized catalyst obtained by this process contains at least 1%.
by weight of carbon from the sulfurization auxiliary of formula (I), based on the total weight of the catalyst in oxide form. 12. The method of claim 11, characterized in that it is under conditions such that the sulfurized catalyst obtained in accordance with means of this process contains at least 1.5% by weight of carbon from the sulfurization auxiliary of formula (I), with respect to total weight of the catalyst in oxide form. 13. Process according to any one of claims 1 to 12.
characterized in that it comprises one or more additional steps.
performed before and / or after said first and second steps, or interspersed between these two steps. 14. Process according to claim 13, characterized in further comprises, after said second step, a passivation step catalyst. 15. Method according to any one of claims 1 to 14, characterized in that it comprises no deposit, on the surface of the catalyst, of carbon sources other than the sulphurization formula (I). 16. Use, in order to improve the performance of the processes of sulfurization of catalysts for the treatment of hydrocarbons, or more sulfurization auxiliary (s) of Formula (I):
in which :
R1 denotes a hydrogen atom or a group linear or branched hydrocarbon, saturated or unsaturated, comprising from 1 to 30 carbon atoms;
R2 denotes a divalent hydrocarbon group linear or branched, saturated or unsaturated, comprising from 1 to 8 atoms of carbon, substituted with one or more -OH, -OR, NH2 groups, -NHR, -NRR ', with R and R' denoting alkyl groups comprising from 1 to 4 carbon atoms;
R3 denotes a linear hydrocarbon group or branched, saturated or unsaturated, comprising from 1 to 30 carbon atoms. 17. Use of a sulfurization aid according to claim 16 in the catalyst sulfidation processes comprising several metal oxides, in order to improve the stoichiometry of the sulphurization of the metalliferous oxide (s).